


Heart Beats

by DoreyG



Category: Justice League & Justice League Unlimited (Cartoons)
Genre: Alien Biology, Anal Sex, Bruises, Emotional Hurt/Comfort, First Time, Friends to Lovers, Kink Exploration, M/M, Marking, Multiple Sex Positions, Other, Post-Episode: s02e11-12 A Better World, Rough Sex, Telepathy, Treat
Language: English
Status: Completed
Published: 2016-08-13
Updated: 2016-08-13
Packaged: 2018-07-25 21:08:40
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,469
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/7547309
Author URL: https://archiveofourown.org/users/DoreyG/pseuds/DoreyG
Summary: <blockquote class="userstuff">
              <p>He's become strangely aware of Clark lately, like a beacon through the night. He finds himself tracking the man in battle, watching him as he grabs a quick bite to eat in the Watchtower canteen, even tracking his thoughts as he goes around his ordinary life down in Metropolis. He knows how he feels, thinks it impossible <i>not</i> to know how he feels with thousands of years experience behind him, but he's still not quite sure what to do with it.</p>
            </blockquote>





	Heart Beats

**Author's Note:**

  * For [Martianico](https://archiveofourown.org/users/Martianico/gifts).



"We couldn't really become like them, could we?"

He's been expecting this visit ever since they left for the Watchtower, leaving a smugly free Lex Luthor in their wake. Clark was quiet all the way back, and while that shouldn't have particularly stood out - everybody was quiet, even the Flash reduced to quietly uncomfortable shifting - it... Did.

He's become strangely aware of Clark lately, like a beacon through the night. He finds himself tracking the man in battle, watching him as he grabs a quick bite to eat in the Watchtower canteen, even tracking his thoughts as he goes around his ordinary life down in Metropolis. He knows how he feels, thinks it impossible _not_ to know how he feels with thousands of years experience behind him, but he's still not quite sure what to do with it.

Yet.

He turns in his chair, the one he specifically arranged to face the window, and takes Clark in. Notes, with not a little sympathy, the nervous shift of his hands and the worry that still lingers so clearly in his eyes, "I wish that I could reassure you."

Clark's lips purse together for a moment, but ease only a second after. He has seen the man angry perhaps once, twice at the most, and so it makes sense that it would not linger here. He slumps in the doorway for a handful of breaths, then gathers himself enough to actually step in, "don't worry, I knew you couldn't."

"I may be able to read minds," he watches Clark for a long second, eventually gathers himself enough - from the surprise, the slightly thrilling one, of having Clark in his room - and gestures to the chair opposite his own, "but I cannot predict the future."

"No," Clark sighs, and slumps obediently down.

"Though life would probably be significantly easier, for all of us, if I could."

"I don't know," Clark says mournfully, and then actually manages a chuckle. Sits back comfortably in the chair, with an only faintly wan smile gracing his lips, "I've met a few people who could see the future, while out and about. Most of them were supervillains. Seems a pretty miserable power to have, based on that evidence."

He finds himself thinking about Clark's lips as often as he finds himself thinking about Clark. Which is ridiculous, of course. He is a Martian, he may have moderated his appearance to be a touch less terrifying to those he protects but he's still entirely alien underneath. He should not be attracted to anything that looks even remotely human. Should not be attracted to full lips, to dark hair, to such beseeching eyes...

But he is.

"I just wish," Clark is saying, tone soft and slightly miserable yet again as he leans forwards with his hands clasped between his knees, "that we _could_ know, you know?"

Perhaps he is already growing to appreciate the aesthetics of this strange new world, to immerse himself in the culture as a matter of survival. 

Or perhaps it is just Clark himself, motivating his every thought. _Clark_. Perhaps he thinks so often of those full lips because the smile the man usually wears on them can only be described as enchanting. Perhaps he thinks so often of that dark hair because he knows how it looks ruffled in the wind, when Clark is flying as fast as he can to save lives. Perhaps he thinks so often of those beseeching eyes because he knows of the sheer _goodness_ of the man that lies behind them.

"...I'm being silly, aren't I?"

Perhaps he is getting distracted by Clark Kent, yet again. He blinks a little, drags himself slowly back to reality and the somewhat upsetting prospect of the man sitting miserably before him, "not at all. It is a legitimate worry, and one we all share."

"Except for the Flash, of course," Clark smiles a little, briefly. Soon lets it fade to the old misery, in a way that hurts him more than he was expecting, "I just don't understand how we could've fallen so far."

"No."

"Turned so much from what we believe in," Clark snaps, balls his fists briefly on his thigh before releasing them. Yet again there is no rage, no burning fury like Batman keeps tucked away just on the inside. There's only disappointment, a baffled sadness at the world proving itself so much worse than his hopes yet again, "we were _dictators_. Mass murderers, for heaven's sake! We'd decided what was right, and we were determined to make the rest of the world pay for our vision."

"I know," he says, inclines his head thoughtfully as he thinks through his next words. Because Clark deserves consideration, has always deserved that at the very least, "to see us all so similar, and yet so different... Was a shock. And it would be easy to say, in the face of that shock, that nothing of the sort could ever happen here."

"It couldn't," Clark nods in desperation, that beseeching look still lingering in his eyes. He cannot understand why the man has any villains, when he's capable of that look, cannot understand why anybody stands against him at all. He sees that look, and he wants to transform himself into a better creature just to make Clark proud, "we're all good people, all _moral_ people. We know what's right, what's just. We _wouldn't_."

"...But."

"They probably never thought that they ever would, either," and Clark slumps a little, frowns again. He regrets it, almost immediately, but sometimes being a better creature means telling the truth even when it's unwelcome, "they once knew what was right, and what was just. They probably even had morals, they were _definitely_ once good. They were exactly like us. Except..."

"I am sorry," but that doesn't mean that he can't be kind. As kind as he can possibly manage, with this man that he cares about so deeply slumped in front of him like a children's toy that has had all its strings cut, "you come here for reassurance, and I only remind you of that which you'd rather forget."

"I'm reminding myself, J'onn," Clark says softly, actually summons up a smile at him - small, and genuine, and so much more than he deserves, "and you are reassuring me."

"By telling you that there's no possible way to know the future, and musing that we could very well turn into the alternate versions of ourselves?" He huffs a little, shakes his head fondly as Clark only keeps smiling at him, "I must admit, I am starting to think that I will never be able to stop finding Earth-based customs strange."

"If I wanted somebody to laugh loudly and pretend that nothing was wrong, I would've gone to the Flash," Clark says wryly, actually reaches out to gently tap his nose, "if I wanted somebody to fiercely reassure me that we were fine and that there was no chance of anything changing that in the future, I would've gone to John. But I chose you instead, and I stand by that."

"I-" He starts, set slightly off balance by the casually intimate touch. Actually has to clear his throat, before his brain deigns to start working again, "I am flattered, Clark. But may I ask why?"

"Because I wanted the truth," Clark shrugs, an only slightly odd motion while he's still in his brightly coloured costume, "Not Wally's overly optimistic version of it, not John's highly biased version of it... And not Batman's highly pessimistic version of it either, for that matter. I know you respect me enough to give me the actual facts, no matter how unpleasant they may be."

"The first time we met you saved my life," he offers honestly, caught off guard by that smiling honesty - that sheer sincerity, that only Clark really seems able to manage - yet again, "I will always respect you, Clark."

"Good to know," Clark laughs, smiles at him fondly for a long few seconds - regard shining so clearly from his eyes that the brightness of it rivals the sunlight - with only the slightest twitch around his mouth to show the thoughts underneath, "and... There may be other reasons."

"Other reasons?" Now that he actually pays attention, forces himself to focus on more than that beautiful care in Clark's eyes, he can feel the shape of those thoughts. He doesn't delve too deep, because he knows that Clark was raised as a human and they do so value their privacy, but what he catches is enough to make him frown - the frenzy of them, the firm determination sitting unmoved in the middle of that frenzy, "I... See. I must warn you, Clark, if you only start trusting green people your circle of friendship may shrink considerably."

"Was that a joke?" Clark asks, and what would be a mocking question from anybody else instead comes out as sheerly overjoyed, "no, don't mind, I can guess from context. The others would reassure me, sure, but they wouldn't... Comfort me. If you get what I mean."

"I do not," he says, deciding that honesty is the best option yet again, "entirely 'get' what you mean, Clark."

"Everybody in the league is a wonderful person, to the point where I often feel humbled to even be in the same room as them," Clark offers honestly, meaning every single word. Because of _course_ he does. If there's one thing that Superman isn't, no matter what Lex Luthor often enviously thinks, it's insincere, "but they don't _calm_ me, not like you do."

"I... See," something is happening here, something strange and wonderful and possibly entirely unexpected. He shifts a little, at the pressure of it in the air, tries to remain as calm as possible in the face of it for Clark's sake, "yet again, I must repeat-"

"That earth culture is weird. Don't worry, I get it," Clark waves his hand, laughs a little. The sound is bright enough to distract him from all his woes, bright enough to drag him down that rabbit hole of worshipping Clark yet again... Until the man reaches forwards again, gently places his hand on his knee like an offer, "but I'm telling the truth, J'onn. You calm me down in a way that nobody else can, especially these days."

He looks down at the hand on his knee, the most pleasant kind of incredulous that he's ever been.

"And if I can do the same for you..."

"Is this what is known as a proposition by humans?" He gathers up the courage to ask, only barely stops himself from wincing away from his boldness in the next moment.

"I suppose," Clark turns bright red at the proclamation, as he both expected and feared. But he doesn't flinch back, doesn't even particularly move away. He removes that hand, that ever so warm hand, from his knee - but that seems more for the sake of his comfort, than anything, "not, er, not in a 'tumble in the hay' sort of way, though."

"We are in space," he points out absently, somewhat distracted - yet again - by wondering how far down Clark's blush goes, "there is no hay in space."

"You know what I _mean_ ," Clark gives him a faintly peeved look for a long few seconds, before it abruptly - and charmingly - transforms into something worried and faintly unsure, "or, uh, I sure _hope_ you know what I mean. I'm not looking for a one night bout of comfort, J'onn, I'd like... God, Lois must be laughing at me from earth right now. I'd like something _more_."

"Something-?" He cuts himself off, when he realizes the question is futile. Has to breathe for a long few moments, just to get enough air back into his lungs to answer, "you are proposing a romantic relationship."

"I _like_ you, J'onn," Clark says, that old sincerity back in such force that it's all he can do not to fall to his knees and worship in the light of it, "I've always liked you, ever since we met that first time. You're brave, you're smart, you're probably the best person amongst all of us... And this whole business only reminded me of that all the more. I'd like to at least try for something, before-"

"Whatever the future may hold?" He asks quietly, letting a new plan settle into his mind with all the clarity of something truly _right_.

"...Whatever the future may hold," Clark says, also ever so quiet, and reaches out again like he needs the contact. Latches onto his hand this time, his fingers skittering over the back of it like he's not sure if he's allowed to touch more intimately yet, "I'd like to help you, just as much as you help me. And if you're willing-"

He turns his hand in Clark's grip, takes hold so simply that a part of him marvels at the fact that they haven't done this before.

"-I think that we could be really good-"

He smiles a little, at the thought. Shifts forwards almost absently, his hand still firmly gripping Clark's like a lifeline in a storm.

"-For each- _mmmph_!"

And Clark's lips, full and smiling and always prepared to say the best possible thing, are just as soft as he was imagining.

He's never really experienced kissing before. In his natural form his lips are one of the least sensitive areas of his body, so it made little sense to lavish attention on them and not elsewhere. But in this form... Once Clark starts to respond, quickly and eagerly, it is an entirely unexpected source of pleasure. A slightly wet, entirely absorbing sort of thing that could happily enchant him for hours.

Or maybe that's just Clark's sheer presence. He never really thought that he'd ever get to have this, but now that he is it's intoxicating in a way entirely unexpected. He kisses Clark, he falls further into Clark's orbit, and it's like an entire new universe has opened up between the two of them. A better one, a utopia the Justice Lords could've never dreamed of.

"You see," Clark manages, dreamy and even a little _breathless_ when they finally separate from each other, "calming."

"I am glad I could help," he says, and cannot quite help a little shudder as Clark's answering laugh gusts over his lips. This new sensation is one to keep an eye on. This new connection with Clark... Is _definitely_ one to do the same with, "would you like me to attempt to calm you more, or is that far enough for tonight?"

"I-" Clark turns bright red again. From his new vantage point, pressed up against the man, he can see it stretch even further down his chest, "I don't want to push. I know it's been a while for you, and all of this is quite a lot, and-"

"Do you want to?" He asks, bold yet again. It still feels strange on him, almost uncomfortable, but considering the results it got him last time he is entirely willing to try it.

"Do you?" ...And considering the results he gets this time, Clark's face lighting up with hopeful determination, he is definitely filing such tactics away for future use.

He smiles, and leans in for another kiss. Is surprised, not to mention pleased, when Clark somehow manages to respond with even more enthusiasm this time. His tongue, he notes absently as they quickly slump in the direction of the floor, is an area even more sensitive than his mouth. Yet more information to keep in mind for the future, a steadily expanding database entirely driven by _Clark_.

The man doesn't make a sound when they land on the floor. Gives only the softest moan, when he braces himself on top of him and continues kissing him. Clark would be a pleasure to kiss in any situation, he has long suspected and is now rapidly having confirmed for him, but the intimacies of this one are especially absorbing. He could spend all his life on top of Clark, all his remaining days swallowing the man's moans and feeling the strength thrumming through his body.

"Um," an impression only confirmed when Clark finally pulls back, looks around in confusion for a long few moments and then flushes red again, "we could always move to a more comfortable place, if you want?"

"I am beyond happy here," he smiles, helplessly fond, and tugs the man up into another kiss.

There is no urgency to their situation, it is the middle of the night and he suspects that even Batman will be unwilling to plunge them into another complex investigation so quickly after the last one, but judging by the increasing pitch of Clark's moans he's already looking forward to a continuation. He shifts his hips down, experimentally, and is pleased when he gets a sharp groan and jerk in response - a very encouraging sign, one that it would be impolite not to take.

His clothes in this form are technically non-existent, a manifestation that he indulges in to avoid the Flash's embarrassment and Shayera's amusement. It is easy enough, in this kind of situation, to will them away. To allow his body to shift, just slightly, until they are faded and he is lying bare on top of the one he wants.

Clark doesn't seem to notice for a moment, still lost in their kiss. But then his fingers trail lower, and he jerks so hard in shock that it's only the malleability of his form that stops him from being thrown off entirely. As it is even he wobbles, has to brace himself on the firmness of Clark's chest and appreciate the muscles while he catches his breath. The man's obvious shock doesn't entirely help, an entirely alluring form of his usual sincerity that makes it almost impossible not to lean back in and start tasting again "...Are you sure?"

"Are you going to ask that all night," he murmurs, relenting and allowing himself to move in just a little. To taste the sweat off Clark's jaw, appreciate the lingering salt of it upon his tongue, "or are you going to act?"

Clark hesitates for a second, still taken aback, and then huffs in amusement. Reaches for his waist, and obligingly pulls the top half of his uniform off over his head, "excuse me for being a considerate partner."

"Never," he smiles, also amused. Trails his hands down to appreciate the muscles as they're revealed.

Clark is quick. He has appreciated that speed many times in battle, watching the sheer grace of the man as he shoots through the sky to save the day over and over again, and he appreciates it now. They kiss for perhaps a minute after the top half of his uniform has been removed, hands carefully mapping each other's bodies, and then Clark makes a softly impatient noise into his mouth. Reaches down, and tugs off the bottom half of his uniform too.

Pressed together... He is slightly ashamed to admit, it's almost too much after his long years spent alone. He lets out his own soft rumble, as their bare legs tangle together, can't quite resist pressing his hips down to get more of that sensation. He is discovering the points of pleasure in this form as Clark does. Appreciating the sensation of them, the unexpected warmth in his nerve endings, the sheer _pleasure_ that surges through him with every rolling movement.

It's intoxicating. 

And soon, very soon, it grows even more so. Clark groans, lowly as their hips continue to roll together, and edges his fingers further down his spine. He shudders at the sensation, at the sensation and the thought of how _heightened_ it'd be if he was in his natural form, and so is distracted. He doesn't notice the press of fingers against his hole until it is already, tentatively, happening.

"Clark?" He draws back to ask curiously, when the man stiffens slightly - awkwardly - underneath him, "what would you like?"

"Can I-?" Clark coughs, goes red yet again. He hardly minds. Now, in this position so tangled together, he can properly measure just how far down it goes. At least to the level of his hips, possibly lower - although the swollen state of his cock hardly allows for exact specifications in that regard. It is entirely endearing, and entirely tempting in a way that still excites him, "I mean, would you like it if we-?"

"Inside of me?" He asks, curious, and can't help a little smile as Clark abandons words in favour of a wonderfully overeager nod, "of course, whatever you desire."

"Do you have any...?"

He frowns a little, slightly confused. And in the future, for he can predict this even if he cannot predict the whole of it, he's sure that he'll blame the several minutes it takes to get Clark's increasingly emphatic flailings on the lust coursing through him, "I can easily prepare myself, Clark, there is no need to worry."

Clark frowns at him, seeming faintly dubious even as his hands snake up to grip his hips.

"Unless you would prefer for me to get up," he says, perhaps a touch pointedly. Shifts himself up so he's fully straddling Clark's hips, rubbing his entrance along the length of the man's cock, "and go down to the medical bay, several floors away. And search out whatever is required. And avoid every other member of the league, all doubtlessly also looking for some form of comfort, as I make my way up here..."

"That's fine!" Clark says hurriedly. And by now he must be heading towards a state of permanently red, something that he'd feel bad about... If it wasn't _so_ very endearing, "as long as you're-"

"Clark."

"- _Sure_."

Clark presses in slowly, careful not to harm him despite all his reassurances that such a thing is impossible. He's a little bigger than even he expected, but he doesn't allow the slow stretch of it to distract him from shifting appropriately. The burn of it is something entirely unexpected, something that borders on the glorious. It doesn't exactly hurt, but the lingering edge of it is enough to make him alert. Enough to make him tighten and gasp, enough to make him sure that this is a memory that he's going to file away for any number of cold nights.

...When Clark has to stop alien attacks on earth, of course.

The man doesn't stop until he's seated inside him entirely. And then lingers for a long few seconds, fingers digging heavily into his hips. It's like he's trying to centre himself, but also like he's trying to be kind. Like he wants to be gentle with him still, take care of his pleasure long before he takes care of his own.

It's Clark all over, sheer goodness that he can't help but be fond of. It's also, however, entirely unneeded in this situation. He makes a soft, encouraging noise. Sighs, when that gets only the slowest stutter of Clark's hips, and makes the decision to lift himself up. _Drives_ himself back down onto Clark's cock, a determined thrust that sends pleasure flaring up all over his body.

Clark, at least, takes the prompting. Even if slowly. He circles his hips up in a tentative manner a few times, as if feeling out the ground, and then starts to move faster as he gives an encouraging rumble and thrusts downwards in return. The roughness of penetration soon gives way to a smooth motion, and then to a steadily building pleasure that turns his eyesight white around the edges. It's glorious, becomes more and more glorious with every little movement.

He digs his fingers into Clark's shoulders, absent-mindedly notes how they lengthen. Hears Clark's loud groan beneath him, and knows that the man doesn't entirely mind.

There's a sudden movement, as he dares to dig his fingers in even harder, and then they're flipping on the floor. He makes a soft noise, as his back impacts the cold metal, but impatiently drags Clark in before the man can do more than let his hips stutter with concern. Very little can hurt him, and this angle is - somehow - even better than the first. It allows Clark to go so much deeper, to plough into him with such force that any normal human would doubtlessly be crushed underneath it.

He digs his fingers in even harder, possibly even hard enough to bruise Kryptonian skin and mark it as his own. Clark lets out a desperate noise between a grunt and a yell in response, hitches one leg up over his shoulder and thrusts even harder.

And if he thought the first alteration in position was an improvement, this is even _better_. His vision goes even more white, a steady fade that leaves the world around him alternately blurry and overly sharp. His body clenches around Clark's cock, almost instinctively, and Clark lets out a noise almost like he's dying in response. Starts to move even harder, with even more passion, like he wants to see if he can drive them both through the hard metal floor with the force of their passion.

He digs his fingers in so hard that they almost turn white, almost phase through Clark's solid shoulders and bruise the muscle underneath. Clark lets out one more desperate noise, and jerks his hips so hard that he can actually feel the metal dent underneath them.

And-

He has not come in years, the sting of his loneliness taking away from any physical pleasure that could be found, but as he shudders to completion around Clark he sincerely regrets that he hasn't dedicated all of his long life to mastering such physical arts. Clark manages a few seconds longer, and then lets out a surprisingly soft groan into the skin of his neck and pulses deep within him.

They breathe each other's air for a long few moments. He peels his hands away from Clark's shoulders eventually, and is pleased to see shallow bruises left in their wake. Is even more pleased when Clark eventually manages to remove his hands and pull out, and leaves dark green smudges on his hips in the aftermath.

"J'onn..." Clark starts softly, watching them with wide eyes as he allows himself to stretch back into a more put together form, "if I-"

"You didn't," he interrupts, catching the rest of the thought from Clark's mind. Smiles slightly, as the man blinks at him, and leans in for a briefly sweet kiss, "don't worry. It was not anything to worry about, it was just... Calming."

Clark smiles, looking only a little incredulous, "calming, seriously?"

"As calming as can be," he chuckles, charmed in return, and leans in for yet another kiss.


End file.
